Common rail fuel systems typically include at least one common rail that supplies high pressure fuel to a plurality of fuel injectors, and at least one high pressure pump that supplies high pressure fuel to the common rail(s). These high pressure spaces in an engine's fuel system are fluidly connected to one another through pipes that are located on the engine. Although leakage in these types of fuel systems is rare, it does occur. In order to contain any leak from the high pressure spaces, it is sometimes useful to contain these high pressure spaces within a low pressure envelope. For instance, a high pressure supply line might actually be a double walled tube with the inner tube containing high pressure fuel, and the outer tube enclosing the inner tube and being fluidly connected to drain in order to return any leaked fluid back to tank. For instance, U.S. Pat. No. 6,237,569 to Stelzer et al. teaches the formation of an internal leakage chamber that hermetically encloses lines and connections associated with a common rail fuel system.
In addition to containing leaks, there is an issue relating to detecting leaks. For instance, U.S. Pat. No. 5,685,268 to Wakeman teaches a fuel leakage detector system that issues an alert if the total amount of fuel leaving a high pressure area in the fuel system is less than the mass of fuel entering the same. Although Wakeman and others have taught methods of detecting a fuel leak in a high pressure common rail system, the problem of diagnosing a leak location in order to repair the same can remain elusive and problematic. In other words, detecting a leak is useful, but detection alone will not aid a technician in locating and repairing the leak. Thus, substantial down time and the associated expense can be involved in tracking down and repairing a leak. This can be further compounded in some engine applications where the various high pressure spaces in the fuel system are at different locations that are difficult to access. For instance, some high pressure spaces might require disassembly of other engine related components in order to gain access thereto.
The present invention is directed to one or more of the problems set forth above.